Analgesia and Placebo.pdf

Analgesia and Placebo
February-05-13
5:42 PM
Placebo
- Was believed that it has no physiological effect, but now it is known to have combined
physical and emotional effect
- Naloxone blocks placebo effect on patients! So does this mean it has a biological effect on the
patients
- Placebo associated treatment has shown improvement in more psychological disease rather
than disease with a known biological cause
Testing placebo effects for analgesia
- This study consisted to normal patients and patients with Pain syndrome
- They studied the levels of pain the patient shows in their fMRI and PET scan before and after
the placebo treatment
- There were three stages to this experiment:
1. Expectation or anticipation of pain or analgesia
i. Anterior cingulate, dorsolateral PFC and PAG were activated in this stage (fMRI)
2. Stimulation of analgesic induction
i. Anterior cingulate, medial PFC, PAG, insula, hypothalamus, and BG were activated
(fMRI)
3. Post treatment
i. Both expected and stimulated pain went down
ii. It was seen that the connectivity between rAC, amygdala and PAG were enhanced